clean up

Author: EgorBo

src/libraries/Common/src/System/IO/Hashing/XxHash3.cs

@@ -136,48 +136,27 @@ public static ulong HashToUInt64(ReadOnlySpan<byte> source, long seed = 0)
             uint length = (uint)source.Length;
             fixed (byte* sourcePtr = &MemoryMarshal.GetReference(source))
             {
-                if (length <= 16)
+                return length switch
                 {
-                    return HashLength0To16(sourcePtr, length, (ulong)seed);
-                }
-
-                if (length <= 128)
-                {
-                    return HashLength17To128(sourcePtr, length, (ulong)seed);
-                }
-
-                if (length <= MidSizeMaxBytes)
-                {
-                    return HashLength129To240(sourcePtr, length, (ulong)seed);
-                }
-
-                return HashLengthOver240(sourcePtr, length, (ulong)seed);
+                    <= 16 => HashLength0To16(sourcePtr, length, (ulong)seed),
+                    <= 128 => HashLength17To128(sourcePtr, length, (ulong)seed),
+                    <= MidSizeMaxBytes => HashLength129To240(sourcePtr, length, (ulong)seed),
+                    _ => HashLengthOver240(sourcePtr, length, (ulong)seed)
+                };
             }
         }
 
 #if SYSTEM_PRIVATE_CORELIB
-        public static ulong NonRandomizedHashToUInt64(byte* sourcePtr, uint length)
+        public static int NonRandomizedHashToInt32(byte* sourcePtr, uint length)
         {
-            // We currently use this function only for large inputs from corelib's String.GetNonRandomizedHashCode,
-            // so we don't need the fast path for small inputs.
-            //
-            // if (length <= 16)
-            // {
-            //     return HashLength0To16(sourcePtr, length, (ulong)seed);
-            // }
-            Debug.Assert(length > 16);
-
-            if (length <= 128)
-            {
-                return HashLength17To128(sourcePtr, length, 0UL);
-            }
-
-            if (length <= MidSizeMaxBytes)
+            ulong hash = length switch
             {
-                return HashLength129To240(sourcePtr, length, 0UL);
-            }
-
-            return HashLengthOver240(sourcePtr, length, 0UL);
+                <= 16 => HashLength0To16(sourcePtr, length, 0UL),
+                <= 128 => HashLength17To128(sourcePtr, length, 0UL),
+                <= MidSizeMaxBytes => HashLength129To240(sourcePtr, length, 0UL),
+                _ => HashLengthOver240(sourcePtr, length, 0UL)
+            };
+            return unchecked((int)hash);
         }
 #endif
 

src/libraries/System.Private.CoreLib/src/System/String.Comparison.cs

@@ -864,7 +864,7 @@ internal static unsafe int GetNonRandomizedHashCode(ReadOnlySpan<char> span)
                         if (length >= XxHash3Threshold)
                         {
                             uint byteLength = (uint)length * 2; // never overflows
-                            return unchecked((int)System.IO.Hashing.XxHash3.NonRandomizedHashToUInt64((byte*)src, byteLength));
+                            return System.IO.Hashing.XxHash3.NonRandomizedHashToInt32((byte*)src, byteLength);
                         }
 #endif